Brush-holder.



D. B. FLOWER.

BRUSH HOLDER. APP LIOATION FILED JAN. 29, 1910.

1,101,917, Patented June 30,1914,

DAVID B. FLOWER, OF GLENSIDE, PENNSYLVANIA.

BRUSH-HOLDER Specification of Letters Patent.

Patented June 30, 1914.

Application filed January 29, 1910. Serial No. 540,784.

To all whom it may concern:

Be it known that I, DAVID B. FLOWER, a citizen of the United States, residing at Glenside, in the county of Montgomery and State of Pennsylvania, have invented certain new and useful Improvements in Brush- Holders, of which the following is a specification.

The present invention relates to improvements in brush-holders for direct current motors and generators and particularly to that type of motors employed in connection with street railway service.

The object of the invention is'the construction of a brush-holder having a yielding tension for the brush and a tension which may be readily increased or diminished as the speed of rotation of the commutator may require.

A further object of the invention is to provide means whereby the tension of the spring and consequent pressure of the brush against the commutator may at once be determined.

To this end the construction embodies a brush-holder having a spiral spring one end of which is connected to a bolt or stud in the body of the holder while the free end of the spring bears directly upon the brush. The brush holder is also provided with a positive means for varying the tension of the spring and with a simple and efiective recording mechanism by which means the pressure imparted to the brush may be read at sight. This construction makes it possible to determine and record the best working pressure under varying degrees of speed and load and since the pressure may be adjusted to meet the requirements of a record once established it follows that a greater efliciency of the motor may be obtained and the cost of maintenance greatly reduced.

For a better understanding of my invention reference may be had to the accompanying drawings in which Figure 1 illustrates an end view of a portion of a motor having brush holders constructed according to my invention. Fig. 2 is a detached perspective view of the brushholder with the brush removed. Fig. 3 is a vertical section on the line 33 of Fig. 2. Fig. 4 is a similar section on line 4-4t of Fig. 2, and Fig. 5 is a perspective view of a modified form of my invention.

As shown in the drawings the brushholder comprises a bracket A provided with a guide-way A to receive the brush B and bearings A and A to receive a short bolt or stud C. The stud C is recessed at a point 0 to receive a spiral spring D, one end of which is forced into the recess while the other end is extended as at D, and provided with a plate D which bears upon the brush B. Various means may be employed for turning the stud C, and thereby adjusting the tension of the spring D, but the means 1 prefer is best illustrated in Fig. 4 in which a worm E, is fitted to a portion of the bearing A and adapted to engage teeth C formed upon the stud The worm E is provided with a shaft E the upper end oi which is squared off so that the worm may be turned by means of a suitable key or wrench. The said worm is secured in place by a threaded washer E threaded into a correspondingly threaded portion of the bearing A and in its relation to the worm E, the washer acts not only as a hearing but also as a j am-nut to secure the worm against turning after the proper adjustment of stud C has been made. The face of the bearing A is planed off and graduated to form a dial F, indicating pounds pressure and fractions thereof and upon one end of the stud C, is fastened a pointer Gr, serving to record upon the dial F,'the tension of the spring D.

In the modified form of my invention as illustrated in Fig. 5 of the drawings a form of brush holder is shown the parts being substantially the same except that in lieu of the worm for adjusting the stud C and spring I), I have shown the stud provided with open ings 0, c, to receive a rod by which means the stud may be turned as also a set screw for holding the stud C in position after the same has been adjusted. At one side of the bracket A, of the brush-holder is an extension A, which in some cases is arranged horizontally as shown in Figs. 1, 2, 3 and 4 while in others it is arranged in a vertical plane as shown in Fig. 5. This extension is provided with a slot, a, to receive a bolt by which means it may be secured to the frame of a motor. The portion A of the bracket which serves as the guide way for the brush B, is recessed at a point a in order to permit the spring D, to engage the brush for the greater part of its length or until the brush has been so far worn away as to be practically useless.

Having described my invention what I claim and desire to secure by Letters Patent is:

A brush holder comprising a bracket haw ing a guide-way to receive a brush and bearings to receive a stud, a single rotatable stud mounted in said bearings and provided with gear teeth, a spring haying one end connected to the stud and its other end adapted to engage and bear with yielding pressure upon the brush, a worm gear mounted upon the bracket and adapted to mesh with the gear teeth of said stud for adjusting the tension of the spring, a seetional bearing for said worm gear, one sec tion of which is screw-threaded into the other section whereby the worm gear is adapted to be clasped between the sections of said bearing to securely hold said worm gear in adjusted position, and trunnions earried by said Worm gear, one of the trunnions passing entirely through and extending beyond the adjustable section of the bearing and providing means whereby the worm gear may be operated for adjusting the tension of the sprin In testimony whereof I aflix my signature in presence of two witnesses.

DAVID B. FLOlVER. lVitnesses DAVID S. VILLIAMS, F RANK X. RENNINGER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

